Perhaps you should try some spelling variations:
"article and nonlinear physical" » "article and nonlinear physics", "article and nonlinear chemical", "article and nonlinear optical"
"article and nuclear physical" » "article and nuclear physics", "article and nuclear medical", "article and nuclear optical"

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"article and nuclear physical\") OR (\"article and nonlinear physical\"))".
• Removing quotes may allow a broader search: (( article and nuclear physical ) OR ( article and nonlinear physical )).
• Adding a wildcard symbol may retrieve word variants: (("article and nuclear physical") OR ("article and nonlinear physical"))*.